SQL生手求教这段有无优化空间

SQL新手求教这段有无优化空间？

SQL code

  
create temporary table tbd(id int) select id from d where para <> 1234;

delete from t1 where id in (select id from tbd);
delete from t2 where id in (select id from tbd);
delete from t3 where id in (select id from tbd);
delete from t4 where id in (select id from tbd);

drop table tbd;

新手求教，有无改进空间？怎么改进？

delete t1 from t1,d where t1.id=d.id;

delete t1 from t2,d where t2.id=d.id;

delete t1 from t3,d where t3.id=d.id;

delete t1 from t4,d where t4.id=d.id;




explain …不就知道了吗




探讨

引用:

delete t1 from t1,d where t1.id=d.id;

delete t1 from t2,d where t2.id=d.id;

delete t1 from t3,d where t3.id=d.id;

delete t1 from t4,d where t4.id=d.id;

这样直接删除，比先select出来再删除快吗？……